After the Ravens' 34-17 victory over the Oakland Raiders on Sunday, Harbaugh said Flacco could come back as early as this week, given the initial timetable for his right hip injury. But this doesn't necessarily mean the Ravens would take the starting job away from rookie first-round pick Lamar Jackson, who has won both of his NFL starts.
This decision could represent the biggest one in Harbaugh's 11-year run in Baltimore.
"I'm not going to get into any of that, for a lot of reasons," Harbaugh said. "Whether the decision has been made or not, it's not important for anybody to know but us. If I decide to do it one way or another, I don't want our opponent to know. So, I'm probably not going to announce it for obvious reasons, just to make it tough for our opponent."
Jackson, the No. 32 overall pick, has brought new life to a struggling team. Before Jackson took over for Flacco, the Ravens had lost three straight and were on the brink of being out of the playoff picture. With Jackson, Baltimore (6-5) has won consecutive games for the first time since September and currently owns the No. 6 seed in the AFC.
Jackson's strength has been athleticism, especially in the ground game. His 190 yards rushing is the most in a quarterback's first two starts in the Super Bowl era, according to the Elias Sports Bureau.
Asked if he's done enough to keep the job once Flacco is healthy, Jackson said, "I don't feel I've done enough. There's always room for improvement."
Flacco hasn't been cleared to practice, but he is expected to see a hip specialist this week. The Ravens were told that Flacco would need three to four weeks to recover after he injured his hip against Pittsburgh on Nov. 4.
So, does Baltimore go back to Flacco? He is the winningest quarterback in Ravens history, and he's the more proven passer with more explosive offenses in Atlanta and Kansas City on the schedule the next two weeks.
Or do the Ravens stick with Jackson? He's the hotter hand and he poses more problems for defenses in their preparation.
Ravens players steered clear of questions about a potential quarterback controversy.
"Both of those guys are extremely talented guys," tight end Mark Andrews said. "Whatever happens, we're in good hands."
Flacco, 33, is in the midst of another underwhelming season since winning the Super Bowl six years ago. He has thrown 12 touchdown passes and six interceptions for a 84.2 passer rating.
In two starts, Jackson has produced 518 total yards but a total of three turnovers. Still, he has been winning teammates over.
"It's the Lamar show," receiver Michael Crabtree said. "You just have to sit back and watch because he's electrifying."